Dorset Council have spent £10m buying the former private girls’ school St Mary’s School.
The school, which shut in July, sits on 55 acres of land, with 165,000sq ft. of accommodation, which the Council say provides a unique business case.
Dorset Council leader Spencer Flower said: "This is a significant investment and I am pleased that we have been able to secure it for the benefit of our community.
"I realise people are asking how can we afford it, but this is a clear example of investing to save in the longer term.
"I don't want to pre-empt any decisions about the site, as we want to work with local people and groups first, but I can say that building a facility like this from scratch would cost considerably more.
"This is a unique opportunity and a very exciting chance to create something new that will greatly benefit our community."
The school taught girls aged between nine and 18 since the school opened in 1945. One of St. Mary’s most notable students is Laura Lopes, daughter to the Duchess of Cornwall.